1. Field of the Invention
This invention relates generally to a holder for tool bits, and particularly to a variable-length extension designed to vary the length between a driving object and an object being driven.
2. Description of the Prior Art
Driver socket wrench sets are well known and commonly used in various applications, and generally improve the efficiency of a mechanic using such tools. In particular, it is generally desirable to employ an extension with a socket wrench in order to increase the distance between the driving head of the wrench and the bolt head or nut engaging socket. In view of the varying requirements of the distance between the wrench handle and the associated socket, various proposals have been made for providing extensible extensions for socket wrenches and spin-drive handles alike. Examples of extendible bit holders, and the like, can be found in U.S. Pat. No. 524,770, issued Aug. 21, 1894, to O. Smith; U.S. Pat. No. 854,742, issued May 28, 1907, to C. E. Hill; U.S. Pat. No. 1,203,853, issued Nov. 7, 1916, to C. Contal; U.S. Pat. No. 1,269,413, issued June 11, 1918, to J. H. Finnigan; U.S. Pat. No. 1,349,553, issued Aug. 17, 1920, to J. R. Ayotte; U.S. Pat. No. 1,493,983, issued May 13, 1924, to J. C. Hurley; U.S. Pat. No. 2,382,291, issued Aug. 14, 1945, to A. E. Carlberg; U.S. Pat. No. 2,438,633, issued Mar. 30, 1948, to J. Condor; U.S. Pat. No. 2,592,978, issued Apr. 15, 1952, to F. A. Trimboli; and U.S. Pat. No. 3,306,639, issued Feb. 28, 1967, to C. S. Lyon.
It is also well known to provide spin-drive handles, such as used with a conventional screw driver, with ratchet mechanisms so that the driver can be actuated in a reciprocating manner instead of a continuous rotary manner, or with intermittant removal of the driver from the associated fastener, and the like, being driven. Examples of ratchet drivers can be found in U.S. Pat. No. 393,419, issued Nov. 27, 1888, to F. Chantrell; U.S. Pat. No. 2,815,837, issued Dec. 10, 1957, to P. S. Morgan; U.S. Pat. No. 2,989,881, issued June 27, 1961, to R. P. Lavietes; and U.S. Pat. No. 3,824,881, issued July 23, 1974, to R. B. Wright.
U.S. Pat. No. 2,806,706, issued Sept. 17, 1957, to C. E. Fitch, discloses an insert bit and holder which sets forth a rather conventional manner of retaining a tool bit in a bit holder of a driving tool. In this known arrangement, a resilient split ring is inserted into a groove formed in the surface of a socket formed in the bit holder for engaging with an annular groove provided on the shank of the tool bit for retaining the bit in the holder.